Today is 100th anniversary of the sinking of the Titanic and a question often asked is, could it happen again? Of course it could - in fact, what most people don't realize is that similar tragedies have occurred many times since then.

The Titanic is the benchmark of ocean disasters, and the aura surrounding it has had almost a magical grip on the public. The RMS Titanic sank in the North Atlantic on April 15, 1912, after hitting an iceberg on her way to New York City. The ship carried more than 2,200 people - more than 1,300 passengers and about 900 crew, and the sinking resulted in the deaths of 1,517 people and is etched in the history books as one of the worst maritime disasters ever.

We remember the Titanic because of so many odd things associated with it: The ship was called "unsinkable" and it carried many notable people on board, not only were many lives lost but many lives could have been saved if there had been more lifeboats, it ran into an iceberg in the open ocean, it was on its maiden voyage, and on and on.

But since then, there have been numerous other disasters that the public seems to have forgotten.

The recent capsizing of the Italian cruise ship Costa Concordia (which carried more than 4,200 passengers and crew) resulted in 30 deaths and has captured worldwide attention, but since the Titanic, there have been numerous other ship tragedies.

For example, in 1987 in the Philippines, the passenger ferry Dona Paz collided with an oil tanker, igniting more than 8,000 barrels of petroleum products. More than 4,300 people died and later it was shown that the ferry had far exceeded its passenger and cargo limits.

In 2002, another ferry, the Le Joola, capsized off the coast of Africa and killed more than 1,800. While in 2006 another ferry had mechanical trouble and in high winds sank in the Red Sea, killing more than 1,000 people. One highly publicized disaster occurred in 1994 when the cruise-ferry Estonia sank in the Baltic Sea because of faulty locks, killing 852. There are dozens of other examples.

The Titanic was the most technologically advanced ship at the time, with the latest in navigation and radio equipment. It even had its own newspaper.

But as so often is the case, sometimes technology is just not enough, especially when humans are involved. There is no such thing as a 100 percent safe or "unsinkable" ship, as we learn time and again. The space shuttle, for example, was the most complex machine ever built, with 2.5 million moving parts, but it suffered two catastrophic failures ending in tragedy, as in the 1986 Challenger and 2003 Columbia disasters.

One reason there are bound to be future maritime disasters is the sheer number of ships in the water. It's been estimated there are about four million commercial fishing vessels in the water at any given moment, not to mention the tens of thousands of military ships, oil tankers, cruise liners and pleasure craft.

The Gulf of Mexico is a good example.

It has thousands of shrimp and fishing boats, recreational craft, commercial shipping lanes and don't forget the nearly 4,000 oil and gas platforms that have supply ships constantly departing and arriving.

The oceans have become a virtual interstate highway system, multiplied many times over and critical to global commerce. With that many ships, accidents are bound to happen.

Despite our best efforts and highly sophisticated technologies, human error is the one major unknown that is difficult to control, as we have tragically seen in recent oil spills. No matter how advanced we make ships, they are still operated by people. The English essayist Alexander Pope may have said it best: "To err is human …"